Hydraulic mechanism



J. o. ALMEN 1,903,083

HYDRAULIC MECHANISM Filed Dec. 22, 1927 2 Sheets-Sheet l March 28, 1933.

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gfx/vento@ @QM March 28, -1 O. ALMEN 1,903,083

Y HYDRAULIC MECHANISM Filed Dec. 22. 1927 2 Sheets-Sheet 2 Patented Mar. 28, 1933 UNITED STATES vPATENT OFFICE JOHN O. ALIEN, OF ROYAL OAK, MICHIGAN, ASSIGNOR TO GENERAL MOTORS RESEARCH CORPORATION, OF DETROIT, MICHIGAN, A CORPORATION OI DELAWARE HYDRAULIC MEcHANIsM Application lcd December 22, 1927. Serial No. 241,949.

This invention has to do with hydraulically operated mechanism and particularly to the type of apparatus adapted to operate the valves'of an internal combustion engine through movement by one plunger produced by displacement of fluid caused by movement of another plunger.

The invention has to do with the provision of means for relieving the hydraulic chamber, containing the actuating Huid, ofair which may find access to it and consists in a readily removable fitting containing passages for the discharge of air. From another point of view, the invention consists in the combination with the hvdraulic chamber of a supply chamber adjacent thereto and a readily removable fitting establishing connection between the chambers so that the Huid in the hydraulic chamber may be readily replenished. It has heretofore been proposed to provide passages such as described` but difficulty has been encountered owing lto the fact that the passages become clogged and in case valves are employed. they sometimes fail to function. This difficulty I propose to remedy by forming the passages andmounting the valves in a readily removable plug similar to the usual spark plug so that the operator of the car may quickly replace or repair the clogged or disabled plug.

My invention also relates to certain details of construction of the plug; to the method of attachment of the plungers to the parts which they operate; and various other fea.

tures of construction which will now be described.

My invention also involves the idea of the returning air finding its way into the hydraulic chamber to the supply chamber, whence it may make its escape through the usual discharge passage leading excess oil back to the source of supply.

In the drawings:

Figure l is a vertical section through an engine employing my improved type valve gear.

Figure 2 is a top plan view of a portion of the engine.

Figure 3 is a side elevation.

Figure 4 is an enlarged view of the removable plug shown in Figure 1.

Figure 5 is a view similar to Figure 4 but showing a modification. In the drawings, the reference character 10 indicates a portion of a conventional automobile engine of the type sold under the trade name of Buick but equipped with my improved hydraulic valve gear. The engine is provided with the usual cylinders 12, push rods 14, camshaft 16 and exhaust and intake valves, one of which is shown at 18. To the upper end of the push rod 14 is secured the-'plunger 20 and to the upper end of the valve stem is secured the plunger 22. The connection between valve stem and plunger is a slightly yielding one comprising a resilient pin 23 passing through alined apertures in the valve -stem and the skirt of the plunger. The plungers 2O and 22 work in -bores 24 and 26 respectively formed in a casting 28 and constituting parts of an hydraulic chamber 30 formed in the removable head 32 clamped to the casting 28. Between the bores 24 and 26 a supply chamber 'I5 34 is provided. The upper wall of the chamber 34 and the head 32 are provided with alined passages 36-38 within'which is received the plug 40.A Adjacent its lower end the -plug is exteriorly threaded as at 42 for engagement with similar threads formed in the opening 36. At its upper end the plug is provided with a flangel 43. A gasket 45 is interposed between the flange and the head 32 to prevent escape lof oil. As shown best in Figure 4, the plug 40 is provided with a. central bore 44 enlarged at its lower end as at 46 to receive a tting 48 formed to provide a valve seat 50. With the sea-t co-operates a valve 52 urged into engagement with the seat by spring 54. The stem of the valve is guided in iitting 56 received in the bore 44. The enlarged portion 46 of the bore 44 com'- municates with the chamber 30 through passages 58, as shown. As the plug 40 extends into the chamber 34, it is obvious that Huid may pass from the bottom of thel chamber to the hydraulic chamber 30 by forcing valve 52 upwardly and passing through bore 46 and passages 58. The plug 40 is also provided 100 with passages for the return of air from the upper part of the chamber 30 to the upper part of the chamber 34. Above the fitting 56 in the bore 44 is located the thermal element 59 in the form of a plug threaded in the upper end of the bore and provided with an axial passage 60 communicating through radial passages 61 with passages 62 in the plug 40. The last-named passages communicate with the hydraulic chamber through the clearance 63 between the plug and the aperture 38. The lower end of the thermal element 59 is of conical shape and co-operates with a conical seat formed in the upper end of fitting 56. The plug 40 is provided with a passage 66 leading from the space between the thermal element 50 and fitting 56 to the upper end of the reservoir 34. The plug 40 and fitting 56 are preferably made of steel and the thermal element 59 of a material having a higher coefficient of expansion than steel, preferably aluminum. Obviously, as the parts become heated, the thermal element expands to a greater extent than the plug reducing the gap between the element and the fitting and consequently shutting olf flow of air and oil from the chamber. The thermally controlled vent just described is broadly claimed in my copending application Serial No. 244,7 62 filed January 5, 1928. The chamber 34 preferably extends the length of the engine block and is supplied with oil from the engine lubricating system through conduit 70 equipped with non-return valve 72 to prevent draining of the system should the engine stand for a long time. Excess oil is returned t0 the crankcase through conduit 7 4 and a pressure relief valve may be provided at the entrance to the conduit to insure the maintenance of the desired pressure in the chamber 34 at all times.

In the operation of this device the rotation of the camshaft 16 moves push rod 14 and plunger 20 applying pressure to the fluid in the chamber 30 forcing piston 22 downwardly unseating the valve 18. As the passages 63, 62, 61, 60, 66 are at all times at least partially open any air which may be in the hydraulic chamber, together with a small quantity of oil, will be forced from the chamber 30 into the chamber 34 on the operating strolre. This oil and air will be discharged into the supply7 chamber adjacent its upper end and will eventually be carried off through the conduit 74. Un the return stroke of the push rod, the spring illustrated as of the so-called rat trap type will return the valve 18 to seating position, and thereafter oil will pass from the supply chamber 34 past the valve 50 into the hydraulic chamber 30. llhis oil will move under the iniuence of the pressure in reservoir 34 and also by virtue of the suction produced by the downward movement of the plunger 20. ue suction is more pronounced where,

as in this case, the plungers are attached to the push rod and valve stem. Note that the replenishing oil is taken from the bottom of the supply reservoir and is, therefore, free of air.

The bolt 82 serves as a stop, limiting the upward movement of the piston 22 and is articularly useful in cases Where the piston 1s not connected to the plunger.

In Figure 5,1 have shown a modification in which the plug is in two parts, and 100. The part 90 contains the valve seat 50,l the valve 52 and the passages 58 and thus provides for the passage of fluid from the supply chamber to the hydraulic chamber. Ylhe part carries a depending sleeve 102 containing a thermal element 104 having its upper end 106 of conical shape co-operating with a conical seat 108 formed on the part 100 and terminating in an axial passage 110 discharging to the atmosphere. The thermal element 106 is of less diameter than the internal diameter of the sleeve 102 providing an annular passage communicating with the interior of the chamber through apertures 112. With this construction the chamber 30 is supplied with oil in the same manner as before but the air and oil are discharged from chamber 30 through the passages 112,the annular space about the thermal element 106, the space between the end of the thermal element and the seat 108, and the axial passage 110 to the exterior of the chamber. The oil thus passing off returns to the crankcase through suitable passages, not shown. As all of the parts illustrated are enclosed, as suggested by the fragmentary showing of a cover at 150, Figure 1, there is no opportunity for the oil to get dirty. While in the form of construction shown in .Figure 4, it is merely necessary to apply a wrench to the upper end of plug 40 to remove it, in the form shown in Figure 5, the portion 100 must first be removed thus permitting the introduction of a suitable tool to remove the part 90 which is threaded into the top of the supply chamber. rlhe part 100 may be bolted or other- Wise secured to the head 32, a gasket 114 being arranged to seal the joint against the escape of fluid.

Vhile in both instances my plugs embody means for the admission of oil to the hydraulic chamber, as well as means for venting air. it is obvious that one or the other of these functions may be dispensed with if desired. However, it is of importance that the parts containing small vents and valve controlled passages be arranged for ready removal and replacement so that trouble arising from clogged passages and failing valves may be quickly cured.

l claim:

1. Hydraulic valve mechanism comprising an hydraulic chamber, operating and operated plungers working in the chamber, a

supply chamber, and a removable fitting connecting said chambers, said tting being provided with a valved passage for the admission of fluid from the supply chamber to the hydraulic chamber and with a passage for returning air and fluid from the hydraulic chamber to the supply chamber.

2. In the combination as defined in claim 1 said last-named passage connecting the upper portions of the chambers.

3. In the combination as defined in claim 1 said first-named passages connecting the lower portions of the chambers to insure against the passage of air from the supply chamber to the hydraulic chamber.

4. In an hydraulic valve operating system, an hydraulic chamber, a piston working in the chamber, an engine valve yieldingly -connected with the piston, means for yieldingly urging the valve towards seating position, and means for causing displacement of fluid in the chamber for operating the piston.

5. The combination as defined in claim 4, the yielding connection between the valve and piston comprising a resilient pin secured oentrally to one of the parts and at its ends to the-other part.

6. A fitting for hydraulic valve gear comprising a threaded plug having a passage therethrough, a valve seat removably secured at one end of the plug and passage, and a valve co-operating with the seat.

7 A fitting for hydraulic mechanism comprising a removable plug having a passage therethrough and a thermal element associated with the passage for controlling the flow therethrough.

8. Hydraulic valve mechanism comprising an hydraulic chamber, operating and operated members working in the chamber, a supply chamber, and a fitting provided with a passage establishing communication between the upper portion of the hydraulic chamber and the supply chamber for the discharge of air from the former, said fitting being accessible from outside said chambers and readily removable therefrom for replacement or repair, and thermally operated means for controlling said passage.

9. An hydraulic operating mechanism including a base portion and a head portion forming therewith an hydraulic chamber, said base portion having bores therein communicating with the hydraulic chamber; operating and operated plungers fitting said bores, a reservoir between said bores, and a. valved passage leading from the reservoir to the chamber.

10. An hydraulic operating mechanism comprising a base portion having a plurality of pairs ofbores therein for operating and operated plungers, va cover for said base portion provided with a plurality of hydraulic chambers, one for each of said pairs of bores.

11. The combination defined in claim 10 and a reservoir between said bores and a valved passage leading from the reservoir to the chamber.

12. Hydraulic valve mechanism comprising a base member provided with spaced bores, plungers reciprocating in the bores, and a removable head provided with a passage connecting said bores and constituting n connection therewith the hydraulic cham- 13. Hydraulic valve gear comprising a base member provided with spaced bores, pistons or `the like adapted to be moved back and forth in said bores, the portion of the base member between said bores being formed to provide a reservoir, a head member, said head member and base member being shaped to provide an hydraulic chamber extending between said bores, said base member being provided with an aperture leading from said reservoir to said chamber.

14. Hydraulic valve gear comprising a base member having pairs of spaced bores, pistons reciprocating in said bores, the portion of the base member between said bores being shaped to provide a reservoir extending lengthwise of the member, a head member, said head member and base member being formed to provide separate hydraulic chambers connecting each of said pairs of spaced bores, and a passage. leading from said reserlvoir to each of said chambers.

15. In hydraulic operating mechanism, the combination of an hydraulic chamber, an operating plunger, an operated plunger, a reservoir, a wall separating the reservoir and chamber, a fitting mounted in the said wall and provided with a passage for the admission of fluid from the reservoir to the chamber, the chamber being provided with an opposite wall having an aperture therein in line with the fitting through which the latter may be removed for replacement or repair, and means for closing said aperture.

16. In an hydraulic valve operating system, the combination of an hydraulic chamber, operating and operated plungers working in the chamber, a supply chamber adjoining the hydraulic chamber, and a removable fitting projecting through one of the chambers and extending into another of the chambers, said fitting being provided with a valved passage for the admission ofoil from the supply chamber into the hydraulic chamber, said fitting being provided with a passage leading from the top of the hydraulic chamber and discharging into the supply chamber for the passage of air and oil from 

